Production of solvents



Dec. 7, 1948. 1 c. MORRIS O PRODUCTION OF SOLVENTS Filed June e, 146

NN mm aolvNolDvai wnowAv aolvavds Hare/M HV1/flamme. L c MORRIS ATTORNEYS -mmumw lll substantially complete conversion of the olens to alkyl benzenes.

to 400 F. 'I'he operation was conducted in a manner to produce a low odor solvent boiling in the range 350 to 450 F. and with moderate solvent power. Properties of the product were as follows:

API gravity (60 F.) 51.3 Index of refraction C.) 1.434 Bromine number Zero Aniline point 71.4 .Kauri-'but-anol value, cc. 35.0 Flash point, F. 130.0 -Eldor Good When operating with the high derxSity-boron'.l

fluoride complex catalysts, recycling of the heavy catalyst material is effectedy through lines VT Y and 22 by pump 23. Eiuent from*theaikylationV chamber is discharged through line 25 to the catalyst separator 2l where lgravity.separation.-..1

into hydrocarbon and catalyst phases occurs.

The heavy catalyst phase is restored to culating catalyst stream through line 28, while the hydrocarbon. phase flows throughline 2.0i to the washer Where traces-of catalyst:y are rre'- moved. The effluent stream then passes through line 31! to the drier 32 and from thence tothe stripping column 33; via linell` containing pump 35. Unreacted benzene is.k driven overhead through the recycle line 302.1;0 .storage H. Jrude alkylate is conveyed to the vacuum fractionator 31 via line 38 containing pump Ml'. Light ends and heavy bottoms are removed through lines lili and 42 respectively, and purified alkyl benzenes are discharged through line 43. containing valve 44'. The low odor paraiiin mixture froxnseparator 8 is ldrawn through line 45 containing valveI 46 and commingled with the alkyl benzenefrom i line 43 in line-M` containing-'pump 48. By sui-table adjustment of valves-M and 46, solvent power of the product may be adjusted as desired.-

In the practice of the invention, thelparailnic feed stock employed should bea low odorr'rhaterial since more efcient operai-,ioni canlbesecured with suchstocks. However, 'slightly offodor materials can often be' employed, if-tlrei fraction obtained is discardedor otlieryvise'uti` lized, since the malodorous products usually are removed in this manner;

In the alkylation step, the aromatic-substance may be benzene or its homologues, Xyl'enes', or other like substances.' The l olenic alkylating agent may comprise-high-boiling olefins -or olefin mixtures boiling in the range'l between 200 and- 500" F. and including-oefins O f'not 'less than seven or more than 18A carbon atoms tothe` molecule. A- preferred source of suc-h mixtures isfound in the 200 to 500 F. fraction from catalytically cracked gas oils or high boiling naphthas, ,suchi as,l for ex. ample, those produced' in a Cycloversion process.

By suitable adwjustment of thefboiling range, low odor solvents of high-"solventpower can be manufactured for use in various specic processes. Obviously this range will be limitedby the 'particular fractions employed as feedstc'cks.A When operating with the highly branchedalkyl-ateshereinbefore mentioned, solvent fractions boiling between about 325 and about 55091:'.y can beproduced. In instances Where: very high solvent power is desired, the larger proportion of aromatic alkylate mayprovide eyen'higher boiling fractions should such be desirable'.l Example r Employing theprocess of they present invention, a solvent was prepared from feed stocks comprisingv heavy HFalkylate, benzene, and .a Cycloversionolen concentrate-boilingin the.'ramires35`0I Example II Thefprocess'of. Example I was repeated employing the same feed stocksbut in a manner to `prod uce'alovvv odor-solvent boiling in the range .y 35,0 to 450 F. and with high solvent power. Properties of the product were as follows:

API gravity (60 FJ, 38.6 Index of refraction -(20 C.) 1.475

Bromine number Zero Kauri-butanol Value, cc Flash point, F. 130 .Odor Good Aniline point, "F', 25

A signicant featurel of the present process lies in the manner of fractionation employed to-prvide-'cuts boiling in the desired range. Distillation is eiected by the use-of steam, thus reducing-the-fractionation temperature. w By operating in-this manner'the tendency towardl odor development often observedwhen the feed stock is heated at or near the boiling point is substantiallyl reduced. By the employment of air-free steam' in the distillation andthe exclusion of air from the system by suitable flushing with inert' gas any deterioration of the product by oxidative processes is substantially veliminated and the preferred low odorL characteristics of the feed stock are maintained. l

Another advantage of thev invention lies in thev aikylation step whereby'solvent power `in the product -is regulated Yover a broad range. The aromatic alkylate produced in this step is of very high solvent power and when comming'led with the low odor paraini'c fractions produced in thev distillation step, contributes 'solvent power in a direct ratio with theproportion present. By suitalble adjustment of this step solvents vcan be prepared for a variety of uses. For example, where it is desired to prepare a solvent for insecticides in which the .concentration yof active base isfsayl 5 per cent, the alkylation step is .operatedV at a low rate, since a very small. proportion of cyclic constituents, will provide vample solvent power. If, onthe. other hand, a concentration of v50 per cent active basewere desired, a .suitable solvent; could be prepared by adjusting, the alkjgrlatingv stepto provide a larger proportion ofthe product stream.. whereby the increased solvent" power' would be obtained.` v

Having described my invention and explained; its'foperatiomjI claim:

1. A process for producing a'solvent having'low odor intensity and controlled solvent power which comprises: fractionating the product resulting from hydrofluoric acid alkylation of a low-boiling isoparaiiin with a short chain olen; withdrawing a fraction boiling above 300 F.: removing dissolved oxygen lfrom saidfraction by blowing an, inert odorless igasI therethrough; steam distilling, said4 fraction with air-free steam; 4maintaining 5 non-oxidizing conditions in such dist-illation by injecting inert odorless gas; withdrawing an overhead product comprising water and hydrocarbons; introducing said overhead product and inert, -odorless gas into a settling zone and separating the liquids therein into a substantially odorless hydrocarbon layer and a water layer; withdrawing said hydrocarbon layer: concomitantly alkylating benzene with a high-boiling olefin concentrate from a process for catalytically cracking high-boiling naphtha in the presence of a catalyst comprising boron fluoride; yseparating residual benzene and catalyst from the resulting aromatic alkylate; distilling said aromatic alkylate under vacuum in a fractionation Zone; withdrawing a fraction of aromatic alkylate iblending said fraction of aromatic alkylate with said substantially odorless hydrocarbon layer withdrawn from said settling zone; and controlling the solvent power of the resulting solvent by controlling the percentage of aromatic alkylate added thereto. l

2. A process for producing a solvent having low odor intensity and controlled solvent power which comprises: fractionating the product resulting from alkylation of a low-boiling isoparafn with a short chain olen; withdrawing a fraction boiling above 300 F.; removing dissolved oxygen from said fraction by blowing an inert odorless gas therethrough; steam distilling said fraction with air-free steam; maintaining non-oxidizing conditions in such distillation by ,injecting inert odorless gas; withdrawing an overhead product comprising water and hydrocarbons; introducing said overhead product and inert, odorless gas into a settling zone and separating the liquids therein into a substantially odorless hydrocarbon layer and a water layer; withdrawing said hydrocarbon layer: i concomitantly alkylating an aromatic hydrocarbon with a high-boiling olefin; separati ing residual aromatic hydrocarbon and catalyst from the resulting aromatic alkylate; distilling said aromatic alkylate under vacuum in a fractionation zone; withdrawing a fraction of aromatic alkylate; blending said fraction of aromatic alkylate with said substantially odorless hydrocarbon layer withdrawn from said settling zone and controlling the solvent power of the resulting solvent by controlling the percentage of aromatic 4. A process for producing a solvent having low odor intensity and controlled solvent power which comprises: distilling an alkylation product comprising a mixture of highly branched parain hydrocarbons with air-free steam; maintaining non-oxidizing conditions in such distillation by injecting inert, substantially odorless gas; withdrawing a substantially odorless fraction; blending said fraction with a fraction of aromatic alkylate produced by vacuum distilling the product formed by catalytically alkylating an aromatic hydrocarbon with an olefin having from 7 to 18 carbon atoms; and controlling the solvent power of the resulting solvent by controlling the proportion of aromatic alkylate therein.

5. A process for producing a solvent having low odor intensity and controlled solvent power which comprises: distilling an alkylation product comprising a mixture of highly branched paraffin hydrocarbons with air-free steam; maintaining non-oxidizing conditions in such distillation by injecting inert, substantially odorless gas; withdrawing a substantially odorless fraction; blending said fraction with a fraction of aromatic alkylate produced by vacuum distilling the product formed by catalytically alkylating an aromatic hydrocarbon with an olefin mixture boiling in range from 200 to 500 F.; and controlling the solvent power of the resulting solvent by controlling the proportion of aromatic alkylate therein.

6. A solvent having high solvent power and low odor, consisting of a highly branched parafiinic HF alkylate boiling above 300 F. in admixture with an alkylated benzene wherein the alkyl group contains at least 7 and not more than 18 carbon atoms, said solvent having the following properties:

Boiling range, F S50-450 API gravity (60 F.) 38.6 Index of refraction (20 C.) 1.475 Bromine number Zero Kauri-butanol value, cc 80 Flash point, F 130 Odor Good Analine point, F 25 LLOYD C'. MORRIS.

REFERENCES CTED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,418,893 Weiss June 6, 1922 1,833,691 Pew Nov. 24, 1931 2,232,117 Kyrdes Feb. 18, 1941 2,276,171 Ewell Mar. 10, 1942 2,286,504 Parker June 16, 1942 2,349,211 Tulleners May 16, 1944 2,376,119 Bruner May 15, 1945 2,387,323 Gaynor Oct. 23, 1945 

